This invention relates to electro-optical semiconductor devices in plastic packages for providing very low cost interfaces to optical fiber transmission lines.
As used herein, "electro-optical" means a device which converts electric current to light and/or vice-versa. "Light" refers to those wavelengths of electromagnetic radiation to which semiconductive material is, or can be made, sensitive, whether or not such light is actually visible to the unaided human eye. "Optical fiber" refers to single or multi-strand light guides.
In the last decade, the cost of copper wire relative to optical fiber and the increasing use of computers in new applications has increased the need for a very low cost electro-optical devices to interface the computer to various I/O (input or output) devices. Among the many possible applications, those where the computer and the I/O device are separated by no more than about one hundred meters represent a group of applications where cost rather than optical performance is paramount. Two of these are, for example, the "wiring" harness in an automobile and the interconnections between a computer and I/O devices, or other computers, in an office or factory.
There have been many electro-optical semiconductor devices proposed in the literature. A considerably smaller number are in actual use. These devices are typically designed with optical performance as the prime consideration.
While providing the desired optical performance, these devices comprise a great number of parts which are expensive to fabricate and assemble. A recently introduced device employing fewer parts, viz. a ferrule package, a segment of optical fiber, an electro-optical semiconductor device, and a header commonly used for other devices, achieves superior optical performance at reduced cost. However, even this device may be too costly for extremely cost sensitive applications, as for example in the automotive market.
Even though cost is paramount, other characteristics cannot be ignored. For example, the device must be easy to use, achieve a modicum of optical performance, and not require a connector whose cost nullifies the savings obtained from the device.
In view of the foregoing, it is therefore an object of the present invention to provide a low cost electro-optical semiconductor device.
Another object of the present invention is to provide an electro-optical semiconductor device compatible with an inexpensive connector to optical fiber transmission lines.
A further object of the present invention is to provide a electro-optical device having a commonly used package configuration, thereby being compatible with existing manufacturing equipment and requiring little special tooling.
Another object of the present invention is to provide an inexpensive connector for optical fiber transmission lines.
A further object of the present invention is to provide an inexpensive connector for securely attaching to an electro-optical device in accordance with the present invention, yet being easily released when desired or to protect the electro-optical device from undue stress.
Another object of the present invention is to provide an inexpensive electro-optical device having an apertured package for aligning an optical fiber with the light emitting or light sensitive portion thereof.